As Ariel Pink's Haunted Graffiti release their new album, their former drummer has taken legal action against them. Aaron Sperske, who played with the band until May this year, claims he co-wrote the 12 songs on Mature Themes and now wants more than $1m (£637,000) in damages.

"In or about 2008 … [Ariel Pink] formed a musical group," the lawsuit reads. Consisting of Pink (real name Ariel Rosenberg), Sperske, and three other musicians, the band was in the business of "musical performing and recording". From then until 15 May 2012, Sperske claims, he completed his duties "diligently and competently … sharing equally in the profits and expenses", such as the costs and royalties of Ariel Pink's 2010 album, Before Today.

That changed in May, when Sperske says the other members of the group "willfully and capriciously … attempted to expel [him]" from the band. Although Sperske had allegedly helped write and record Mature Themes, in 2011 and 2012, his lawyers indicate he is not listed as co-author and co-owner of the album's songs. According to the lawsuit, Sperske is entitled to royalties from this work, as well as proceeds from the band's live performances – including the concerts since he left.

In addition to lost royalties, Sperske is suing for an additional $1m in punitive damages. Ariel Pink's Haunted Graffiti, the lawsuit reads, "acted with oppression and malice".

Based in Los Angeles, Ariel Pink has been making music for nearly a decade, working with a variety of collaborators and gradually emerging from indie rock's fringes. Before Today, Pink's debut on 4AD, marked a breakthrough, but it is clear there have been growing pains. In June, Pink wrote on Facebook that he had "broken up the band … RIP". Speaking to Pitchfork, the group's publicist said there was "no truth" to that claim.

"I feel like this is definitely the beginning of the end," Pink told Michael Hann in Sunday's Observer. "It's only a matter of time before they end up slaying the father and shove me under the rug."